～まま — as is / leaving it…

1. Basic structure

Component	Structure with ～まま	Meaning	Structure examples
Noun	N のまま	Remain as N	靴のまま / 子どものまま
Na-adjective	Aなまま	Remain in state A	元気なまま / 自由なまま
Verb (done/not done)	Vたまま / Vないまま	Remain as is after doing V / remain as is without doing V	開けたまま / 何も言わないまま
Fixed expressions	そのまま / このまま / あのまま	Keep it as is	そのままにしておく

2. Main meaning & detailed analysis

～まま expresses “keeping the original state as it is” without change. It is a grammatical noun (名詞), so it combines with の/な/だ. The tense/aspect of the main clause determines the overall time; まま only marks the background state.

Vたまま: emphasizes “after finishing V, leave that state as is”.
Vないまま: “while not having V-ed, leaving it as is...”, often implies regret/shortcoming.
Nのまま / Aなまま: keep the current quality/characteristic as is.

3. Illustrative examples

窓を開けたまま寝てしまった。
I ended up falling asleep with the window left open.
靴のまま部屋に入らないでください。
Please do not enter the room with your shoes on.
日本語が分からないまま帰国した。
I returned to my country without understanding Japanese.
この問題はこのままにしておきましょう。
Let's leave this issue as it is.
彼は子どものままだ。
He is still like a child (immature).

4. Usage & nuances

Neutral: merely indicates a maintained state; not inherently evaluative.
Vないまま often carries a feeling of regret/deficiency.
In instructions: そのままにしておいてください (leave it as is).
Compared with っぱなし: まま is neutral; っぱなし implies neglect/negativity (開けっぱなし: left wide open/left open and unattended).

5. Comparison, distinctions, and similar patterns

Pattern	Meaning	Difference	Short example
～まま	Keep the state as is	Neutral; grammatical noun	電気をつけたまま
～っぱなし	Leave as is (left unattended)	Negative, careless connotation	ドアを開けっぱなし
～とおり（に）	As, just as	Refers to “method/standard”, not to maintaining a state	説明したとおりに
～ままに	As told/ordered	Often in fixed expressions: 言われるがまま	好きなままに生きる

6. Additional notes

The tense of the main clause determines the time: 開けたままにしていた (left it open), 開けたままだ (it is still open).
Vる + まま is rarely used, except in fixed phrases like 思うまま（に） (as one thinks/wants), 言うまま (as said), which are essentially nominalizations.
In writing, そのまま/このまま can naturally omit a known subject.

7. Variants & fixed phrases

そのまま / このまま / あのまま
言われるがまま（に）: do as one is told
思うまま（に）/ 好きなまま（に）: as one wishes
～たままにする／～たままにしておく: leave as is

8. Common mistakes & JLPT traps

Using Vる + まま indiscriminately: ×食べるまま → 〇食べたまま / 食べないまま.
Confusing it with っぱなし: in questions, っぱなし usually requires a sense of “neglect/troublesome”.
Confusing it with とおり: ～まま does not mean “according to instructions” but “keeping a state as is”.

Time / State / Experience